Piston-valve



(No Model.) Y 3 sheets-sheet 1`. W. W. ST.`JOHN.

PISTON VALVE.

Patented Nov.- 11, 1884.

(No Model.) I t Wl W. 3 Sheets Sheet 2.

l PISTON VALVE.

No. 308,007. Patented Nov.. v`11, 1884.

y 0c' Mm laye/QQ@ (No Model.)

. 3 sheets-Sheen 3f. W. W. ST. JOHN.

PISTON VALVE.

Patented Nov. 11, 1884.

l/7. 6 azf VILLIAM WV. ST. JOHN, OF ST. LOUIS, MISSOURI'.

PlsToN-VALVE.

SPECIFICATION forming part of Letters Patent No. 308,007, dated November 11, 1884.

Application filedl February 2, 1894. (No model.)

To all whom it may concern,.-

Beit known that I, VILLIAM W. ST. JOHN, a citizen of the United States, residing at St. Louis, in the county of St. Louis and State of Missouri, have inventedcertain new and useful Improvements in Piston-Valves; and I do hereby declare the following to be a full, clear, and exact description of the invention, such as will enable others skilled in the art to which it appertains to make and use the same.

My invention relates to improvements in piston-valves; and the object is to improve their construction so that there is no leakage of steam and their action and operation are more effective, that they can be readily applied to old engines in which it is desired to replace an ordinary slide-valve with piston-valves, and also that they are easily applicable to new engines, and can be constructed at a very small expense, are not liable to get out of order, and can, be accurately adjusted to the bore of the cylinder in which they move.l

The invention consists in the construction of parts and arrangement of details, as will be more fully described hereinafter, and more specically pointed out in the claims, reference being had to the accompanying drawings and the letters of reference marked thereon.

Like letters indicate like parts in the different figures of the drawings, in which- Figure l represents an end view of the valves shown placedin an ordinary steam-chest. Fig. 2 is a plan view of the valves, with the upper part of the casing removed. Fig. 3 is an en'd view of a modification of the saine, adapted to be used as a cutoff. Fig. 4 is a plan view of the same. Fig. 5 is a detail view of the wedge and cap. Fig. 6 is alongitudinal section ofthe modification through the steam-valve. Fig. 7 is an enlarged detail section of one of the piston-valves.

In the drawings, A represents a casing or back placed inside of an ordinary steam-chest, B, and is held to the seat by one or more setscrews, b. The casing is accuratelybored out for the reception of the valves C and D, one being the steam-inlet valve, C, andthe other the exhaust-valve D. These valves consist of a ring, a, snugly iitting into the cylindrical part of thev casing and are cut at one side. They are provided with a dovetail projection,

projection fits a cap, d, having a lug, d', into which the bolt e is tapped. This bolt has a collar, e', bearing against the follower E, and serves to adjust the cap over the projection. At the upper side of each valve is fitted a' tapering key, f, with which the ring a isforced out or expanded against the cylindrical seat. The cap and projection serve to clamp said key when it is driven in farther in the ring as4 it wears, and the cap must be adjusted to suit. The followers fit into recesses turned into the rings, and are held in place by the bolts g extending through the valves. These bolts are extended at one end and have formed on them a collar and pin, h, onto which a yoke, F, secured on the end of the valve-stem G,fits.

This valve-stem passes through the ordinary stuffing-box. The two heads with the rings are connected by a reduced part, H.

In the modification the valves are represented as adapted to be used in connection with any suitable cut-off gear, and in this case the steam-inlet valve C-is formed of a ring, c', having a double wedge, t', extending both ways from the center, and over said wedge the two caps t fit, and are adjusted by a bolt, i2, having right-and-left-hand thread, so thatit can be operated from one end. On the inside of the ring is arranged a lug, k, having a notch, into which one end of thestem 7c engages. The

exhaust-valve is similar in every respect to that shown in Figs. l and 2, excepting that itis made longer, so as to cover the steam-ports and allow a free exhaust of the steam.

In some instances the ordinary steam-chest may be dispensed with altogether, andthe casL ing will then form the steam-chest. In this case I prefer to cast one of the heads with the body of the casing, and the other head is then provided with the usual stuffing-box, as shown in Fig. 6. In this figure the section is represented as taken through the steam-valve for a cut-off, although the valves may be employed of the form shown in Figs. l and 2.. A suitable opening, I, is provided, which connects with the steam-pipe.

It will be readily seen that the ring used in connection with this valve can be readily adapted to any piston by a mere inversion with small change. The ring is virtually a IOy solid ring, and can be readily and quickly adjusted,ifworn,to the cylindrical seat. It forms a perfectly steam-tight joint and is abalanced valve, and will, therefore, operate more economically, and can also be casi er repaired than the ordinary slide-valve. It can be readily adapted as a cut-off valve to any engine.

The casings may be cast onto the cylinderheads, if desired, and connected by a longitudinal pipe-connection, through which the valve-stem can operate. The pipes in this instance are secured by Wrought-iron straps to the oasings with the ports.

Having thus described my invention, what I claim, and desire to secure by Letters Patent, 1s-

1. A split valve-rin g havin g in its outer face a tapering key, and on its inner face a dovetailed Wedge cast thereon, over which a cap fits, which is adjusted by a screw-bolt to form a steam-tight packing by a virtually solid ring, substantially as specified.

2. Apiston-valve provided with a ringhaving a dovetailed Wedge projection on itsinner outer face, to form a steam-tight packing, substantially as set forth.

3. A valve-ring provided with a single or double dovetailed Wedge projection and caps tting thereon, adjusted by a bolt, in combination With a tapered key tting into the outer face of said ring, substantially as and for the purpose herein specified. i

4:. The combination of a pair of pistonvalves having rings provided with dovetailed Wedge-shaped projections on their inner faces, over which caps fit, adjustable by bolts, with a casing, A, forming asteam-chest, as set forth.

5. The combination of piston-valves C and D, provided With rings having tapered key,V

WILLIAM V. ST. JOHN.

Vitnesses:

ALEXANDER SIMON, J. M. YZNAGA. 

